The present invention relates to a process for manufacturing an anti-blooming diode associated with a surface canal and an anti-blooming system obtained by this process applicable more particularly to the formation of frame transfer matrices and more generally to the formation of opto-electronic components.
Anti-blooming diodes are generally formed on the semiconductor substrates of frame transfer matrices using photolithographic processes comprising several photolithographic operations. During these operations inverse impurities are implanted in the substrate for creating under the gates potential wells greater than those of the non implanted parts, the non implanted zones generally bearing the name of surface canal zones and the implanted zones bearing the name of volume canal zones. In this process, each diode is connected to a gate while being isolated from the corresponding volume transfer canal zone by a potential barrier obtained from a surface canal zone which forms an MOS transistor structure, MOS being the abbreviation for "metal oxide semiconductor", whose source is formed by a conventional diode and whose drain is formed by a weakly doped diode whose surface canal is controlled by the gate.
This process has the disadvantage of being poorly adapted to large scale production of frame transfer matrices for the accuracy of positioning the surface canal zones and the volume canal zones depends in this process entirely on that of the photolithographic machines, which does not allow good reproducibility of the frame transfer matrices obtained.